Solar air conditioning for an institutional building in subtropical climate

Air conditioning is one of the major consumers of electrical energy. The most of the ways of generating the electricity today, as well as the refrigerants being used in traditional vapour compression cooling system, produce greenhouse gas emissions which ultimately contribute to global warming. It is therefore necessary to develop process and technology to implementing renewable sources of energy for air conditioning to reduce greenhouse gas emissions and to achieve sustainable development. The use of solar energy to drive cooling cycles for space conditioning is relatively a new and attractive concept which mostly eliminates the need for CFC, HCFC or HFC refrigerants. In this presentation an overview of a hybrid solar desiccant cooling system which has been designed and installed in an institutional building of Central Queensland University, Rockhampton campus, Australia is presented. The conceptual bases of the technology, capability and limitations are outlined. The energy demand, energy consumption, and economic and environmental problem associated with the usage of fossil fuel resources in Australian commercial buildings and the issues of indoor air quality, mould growth and indoor thermal comfort are discussed. Furthermore, experimental and computational results of the performance of installed solar desiccant cooling system is presented and discussed. The results are analysed on the basis of energy savings, solar fraction (SF), primary energy used, coefficient of performance (COP) and desiccant system efficiency. Results showed that the installed solar desiccant cooling system at Central Queensland University can achieve energy savings of 19% with maximum coefficient of performance of 0.83 and desiccant efficiency of 48%.